Methods for altering mass and fertility in plants

ABSTRACT

The invention provides methods altering organ size/mass and fertility or both in plants through the modulation of cell proliferation. The methods involve producing transgenic plants comprising a recombinant expression cassette containing an ANT nucleic acid linked to a plant promoter.

FIELD OF THE INVENTION

The present invention is directed to plant genetic engineering. In particular, it relates to new methods for altering plant mass (for instance organ size/mass) and fertility in plants.

BACKGROUND OF THE INVENTION

Control of organ mass/size and fertility in plants is a significant goal in commercial agriculture. Plant shoot vegetative organs and/or structures (e.g. leaves, stems and tubers), roots, flowers and floral organs and/or structures (e.g. bracts, sepals, petals, stamens, carpels, anthers and ovules), seed (including embryo, endosperm, and seed coat) and fruit (the mature ovary) are the harvested product of numerous agronomically-important crop plants. Therefore the ability to manipulate the size/mass of these organs/structures through genetic control would be an important agricultural tool. Similarly, induction of sterility in plants is useful in limiting plant pollination and reproduction until it is economically desirable. For example, male sterile plants are often desirable in crops where hybrid vigor increases yield.

The intrinsic plant organ size is determined genetically, although it can be altered greatly by environment signals (e.g. growth conditions). In general, larger organs consist of larger numbers of cells. Since neither cell migration nor cell death plays a major role during plant development, the number of cells in plant organs depends on cell proliferation. Precise regulation of cell proliferation is also necessary for proper development of reproductive organs that make plants fertile. While some basic research has identified genes involved in plant organ development and fertility, little is known about genetic control of cell proliferation or its link to organogenesis including organ size/mass control and fertility in plants. Therefore an important goal is to understand the connection between genes that control organogenesis and genes that control cell proliferation. A great deal of basic research has shown that the components (e.g., cyclin dependent kinases, cyclins and their inhibitors) and mechanisms (e.g., regulation by phosphorylations, ubiquitin-mediated proteolysis) that control the cell cycle in yeast and animals are conserved in higher plants (Burssens, et al. Plant Physiol Biochem. 36:9-19 (1998)).

In Arabidopsis, the developing flower includes the ovule. Wild-type ovule development in Arabidopsis has been extensively analyzed (Robinson-Beers et al., Plant Cell 4:1237-1249 (1992); Modrusan, et al. Plant Cell. 6:333-349 (1994) and Schneitz et al., Plant J. 7:731-749 (1995)). A variety of mutations that affect ovule development have been identified (Klucher et al., Plant Cell 8:137-153 (1996); Elliott et al., Plant Cell. 8:155-168 (1996); Baker, et al., Genetics. 145:1109-1124 (1997); Robinson-Beers, et al., Plant Cell. 4:1237-1249 (1992); Modrusan et al. Plant Cell. 6:333-349 (1994); Ray, A., et al. Proc Natl Acad Sci USA. 91:5761-5765 (1994); Lang, et al., Genetics 137:1101-1110 (1994); Leon-Kloosterziel Plant Cell. 6:385-392 (1994); Gaiser et al., Plant Cell 7:333-345 (1995)), and some of them have been found that specifically affect patterns of cell division (Schneitz, et al. Development. 124:1367-1376 (1997)). Of those, several genes have been cloned; AINTEGUMENTA (ANT) (Klucher et al. Plant Cell. 8:137-153 (1996); Elliott et al., Plant Cell. 8:155-168 (1996)), AGAMOUS, (Yanofsky et al., Nature. 346:35-39 (1990); Bowman et al., Plant Cell. 3:749-758 (1991)), SUPERMAN (Sakai et al., Nature. 378:199-203 (1995)). Because these genes are expressed and function not only in developing ovules but also in various developing organs, analysis of these mutations and genes has provided general information about the control of cell proliferation during plant development.

In spite of the recent progress in defining the genetic control of plant cell proliferation, little progress has been reported in the identification and analysis of genes effecting agronomically important traits such as organ mass/size, fertility and the like through regulating cell proliferation. Characterization of such genes would allow for the genetic engineering of plants with a variety of desirable traits. The present invention addresses these and other needs.

SUMMARY OF THE INVENTION

The present invention provides methods for modulating cell proliferation and thus cell number in plants by modulating ANT activity in plants. Typically, the methods comprise modulating the expression of ANT in plants and selecting for plants with altered size/mass, fertility, or both. In some preferred embodiments, the ANT activity is increased and plants with increased cell proliferation and thus increased cell number are selected. One method for modulating ANT expression is by introducing into a plant an expression cassette containing a heterologous ANT nucleic acid operably linked to a promoter. Examples of possible ANT nucleic acids that can be used include the nucleic acids shown in SEQ ID NO:1 and SEQ ID NO:4. Other examples include nucleic acids that encode the polypeptides shown in either SEQ ID NO:2 or SEQ ID NO:5.

The plant promoters used in the methods of the invention are not critical to the invention. The promoter can be constitutive, inducible or specific for an organ, tissue, or cell. In some embodiments a promoter from an ANT gene, e.g. SEQ ID NO: 3, is used. Expression of the ANT nucleic acids of the invention can be directed to any desired organ, tissue, or cell in the plant. In some preferred embodiments of the invention, the promoter directs expression of the ANT nucleic acid in shoot vegetative organs/structures, such as leaf, stem and tuber. In other preferred embodiments, the promoter directs expression of the ANT nucleic acid in roots. In other preferred embodiments, the promoter directs expression of the ANT nucleic acid in flowers or floral organs/structures, such as bracts, sepals, petals, stamens, carpels, anthers and ovules. In different embodiments, the promoter directs expression of the ANT nucleic acid in seeds (e.g. embryo, endosperm, and seed coat) or fruit.

In another embodiment of the invention, a heterologous gene is expressed in meristematic tissue of a plant by introducing into a plant an expression cassette containing an ANT promoter operably linked to a heterologous polynucleotide. In a preferred embodiment of this invention, the ANT promoter is shown in SEQ ID NO:3.

The invention also provides isolated nucleic acid molecules comprising an ANT nucleic acid that specifically hybridizes to SEQ ID NO: 4, which is isolated from Brassica napus.

Definitions

The phrase “nucleic acid sequence” refers to a single or double-stranded polymer of deoxyribonucleotide or ribonucleotide bases read from the 5′ to the 3′ end. It includes chromosomal DNA, self-replicating plasmids, infectious polymers of DNA or RNA and DNA or RNA that performs a primarily structural role.

The term “promoter” refers to regions or sequence located upstream and/or downstream from the start of transcription and which are involved in recognition and binding of RNA polymerase and other proteins to initiate transcription. A “plant promoter” is a promoter capable of initiating transcription in plant cells.

The term “plant” includes whole plants, shoot vegetative organs/structures (e.g. leaves, stems and tubers), roots, flowers and floral organs/structures (e.g. bracts, sepals, petals, stamens, carpels, anthers and ovules), seed (including embryo, endosperm, and seed coat) and fruit (the mature ovary), plant tissue (e.g. vascular tissue, ground tissue, and the like) and cells (e.g. guard cells, egg cells, trichomes and the like), and progeny of same. The class of plants which can be used in the method of the invention is generally as broad as the class of higher and lower plants amenable to transformation techniques, including angiosperms (monocotyledonous and dicotyledonous plants), gymnosperms, ferns, and multicellular algae. It includes plants of a variety of ploidy levels, including aneuploid, polyploid, diploid, haploid and hemizygous.

“Increased or enhanced ANT activity or expression of the ANT gene” refers to an augmented change in ANT activity. Examples of such increased activity or expression include the following. ANT activity or expression of the ANT gene is increased above the level of that in wild-type, non-transgenic control plants (i.e. the quantity of ANT activity or expression of the ANT gene is increased). ANT activity or expression of the ANT gene is in an organ, tissue or cell where it is not normally detected in wild-type, non-transgenic control plants (i.e. spatial distribution of ANT activity or expression of the ANT gene is increased). ANT activity or expression is increased when ANT activity or expression of the ANT gene is present in an organ, tissue or cell for a longer period than in a wild-type, non-transgenic controls (i.e. duration of ANT activity or expression of the ANT gene is increased).

A polynucleotide sequence is “heterologous to” an organism or a second polynucleotide sequence if it originates from a foreign species, or, if from the same species, is modified from its original form. For example, a promoter operably linked to a sequence which is not naturally associated with the promoter (e.g. a genetically engineered coding sequence or an allele from a different ecotype or variety).

A polynucleotide “exogenous to” an individual plant is a polynucleotide which is introduced into the plant by any means other than by a sexual cross. Examples of means by which this can be accomplished are described below, and include Agrobacterium-mediated transformation, biolistic methods, electroporation, and the like. Such a plant containing the exogenous nucleic acid is referred to here as a T₁ (e.g. in Arabidopsis by vacuum infiltration) or R₀ (for plants regenerated from transformed cells in vitro) generation transgenic plant. Transgenic plants that arise from sexual cross or by selfing are descendants of such a plant.

An “ANT nucleic acid” or “ANT polynucleotide sequence” of the invention is a subsequence or full length polynucleotide sequence (SEQ ID NO:1) which, encodes a polypeptide (SEQ ID NO:2) and its complement, as described, for instance, by Klucher et al., Plant Cell 8:137-153 (1996) and Elliott et al., Plant Cell. 8:155-168 (1996) (see, also, GenBank Accession Nos. U40256 and U41339). SEQ ID NO:4, which encodes SEQ ID NO:5, represents another “ANT nucleic acid” from Brassica. ANT gene products of the invention are characterized by the presence of an AP2 domain, first identified in AP2, this motif is characterized by a region of approximately 60-70 amino acid residues with a highly conserved core region with the capacity to form an amphipathic α-helix and/or to bind DNA (Jofuku et al., Plant Cell 6:1211-1225 (1994); Ohme-Takagi and Shinshi, Plant Cell 7: 173-182 (1995). The full length ANT protein contains two AP2 domains (amino acids 281 to 357 and from 383 to 451 of SEQ ID NO:2) and a linker region (amino acids 358 to 382), and the homology to other AP2 domain proteins is restricted to this region. An ANT polynucleotide of the invention typically comprises a coding sequence at least about 30-40 nucleotides to about 2500 nucleotides in length, usually less than about 3000 nucleotides in length. Usually the ANT nucleic acids of the invention are from about 100 to about 5000 nucleotides, often from about 500 to about 3000 nucleotides in length.

In the case of both expression of transgenes and inhibition of endogenous genes (e.g., by antisense, or co-suppression) one of skill will recognize that the inserted polynucleotide sequence need not be identical, but may be only “substantially identical” to a sequence of the gene from which it was derived. As explained below, these substantially identical variants are specifically covered by the term ANT nucleic acid.

In the case where the inserted polynucleotide sequence is transcribed and translated to produce a functional polypeptide, one of skill will recognize that because of codon degeneracy a number of polynucleotide sequences will encode the same polypeptide. These variants are specifically covered by the terms “ANT nucleic acid”, “ANT polynucleotide” and their equivalents. In addition, the terms specifically include those full length sequences substantially identical (determined as described below) with an ANT polynucleotide sequence and that encode proteins that retain the function of the ANT polypeptide (e.g., resulting from conservative substitutions of amino acids in the ANT polypeptide).

The term “altered fertility” includes any transient or permanent alteration of fecundity including inducing sterility as well as altered initiation of floral development (e.g., flowering time). Sterility can be caused, inter alia, by disruption of pollen development, dehiscence (i.e. male sterility), by disruption of ovule development (i.e. female sterility), or by disruption of pollination/fertilization processes caused by abnormal development of male/female organs (e. g. stigmatic papillae, transmitting tissue of septum). Flowering time is the developmental time or stage when a plant initiates and produces floral tissue.

Two nucleic acid sequences or polypeptides are said to be “identical” if the sequence of nucleotides or amino acid residues, respectively, in the two sequences is the same when aligned for maximum correspondence as described below. The terms “identical” or percent “identity,” in the context of two or more nucleic acids or polypeptide sequences, refer to two or more sequences or subsequences that are the same or have a specified percentage of amino acid residues or nucleotides that are the same, when compared and aligned for maximum correspondence over a comparison window, as measured using one of the following sequence comparison algorithms or by manual alignment and visual inspection. When percentage of sequence identity is used in reference to proteins or peptides, it is recognized that residue positions that are not identical often differ by conservative amino acid substitutions, where amino acids residues are substituted for other amino acid residues with similar chemical properties (e.g., charge or hydrophobicity) and therefore do not change the functional properties of the molecule. Where sequences differ in conservative substitutions, the percent sequence identity may be adjusted upwards to correct for the conservative nature of the substitution. Means for making this adjustment are well known to those of skill in the art. Typically this involves scoring a conservative substitution as a partial rather than a full mismatch, thereby increasing the percentage sequence identity. Thus, for example, where an identical amino acid is given a score of 1 and a non-conservative substitution is given a score of zero, a conservative substitution is given a score between zero and 1. The scoring of conservative substitutions is calculated according to, e.g., the algorithm of Meyers & Miller, Computer Applic. Biol. Sci. 4:11-17 (1988) e.g., as implemented in the program PC/GENE (Intelligenetics, Mountain View, Calif. USA).

The phrase “substantially identical,” in the context of two nucleic acids or polypeptides, refers to sequences or subsequences that have at least 60%, preferably 80%, most preferably 90-95% nucleotide or amino acid residue identity when aligned for maximum correspondence over a comparison window as measured using one of the following sequence comparison algorithms or by manual alignment and visual inspection. This definition also refers to the complement of a test sequence, which has substantial sequence or subsequence complementarity when the test sequence has substantial identity to a reference sequence.

For sequence comparison, typically one sequence acts as a reference sequence, to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are entered into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. Default program parameters can be used, or alternative parameters can be designated. The sequence comparison algorithm then calculates the percent sequence identities for the test sequences relative to the reference sequence, based on the program parameters.

A “comparison window”, as used herein, includes reference to a segment of any one of the number of contiguous positions selected from the group consisting of from 20 to 600, usually about 50 to about 200, more usually about 100 to about 150 in which a sequence may be compared to a reference sequence of the same number of contiguous positions after the two sequences are optimally aligned. Methods of alignment of sequences for comparison are well-known in the art. Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by manual alignment and visual inspection.

One example of a useful algorithm is PILEUP. PILEUP creates a multiple sequence alignment from a group of related sequences using progressive, pairwise alignments to show relationship and percent sequence identity. It also plots a tree or dendogram showing the clustering relationships used to create the alignment. PILEUP uses a simplification of the progressive alignment method of Feng & Doolittle, J. Mol. Evol. 35:351-360 (1987). The method used is similar to the method described by Higgins & Sharp, CABIOS 5:151-153 (1989). The program can align up to 300 sequences, each of a maximum length of 5,000 nucleotides or amino acids. The multiple alignment procedure begins with the pairwise alignment of the two most similar sequences, producing a cluster of two aligned sequences. This cluster is then aligned to the next most related sequence or cluster of aligned sequences. Two clusters of sequences are aligned by a simple extension of the pairwise alignment of two individual sequences. The final alignment is achieved by a series of progressive, pairwise alignments. The program is run by designating specific sequences and their amino acid or nucleotide coordinates for regions of sequence comparison and by designating the program parameters. For example, a reference sequence can be compared to other test sequences to determine the percent sequence identity relationship using the following parameters: default gap weight (3.00), default gap length weight (0.10), and weighted end gaps.

Another example of algorithm that is suitable for determining percent sequence identity and sequence similarity is the BLAST algorithm, which is described in Altschul et al., J. Mol. Biol. 215:403-410 (1990). Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/). This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive-valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as the neighborhood word score threshold (Altschul et al, supra). These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them. The word hits are extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value; the cumulative score goes to zero or below, due to the accumulation of one or more negative-scoring residue alignments; or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLAST program uses as defaults a wordlength (W) of 11, the BLOSUM62 scoring matrix (see Henikoff & Henikoff, Proc. Natl. Acad. Sci. USA 89:10915 (1989)) alignments (B) of 50, expectation (E) of 10, M=5, N=−4, and a comparison of both strands.

The BLAST algorithm also performs a statistical analysis of the similarity between two sequences (see, e.g., Karlin & Altschul, Proc. Nat'l. Acad. Sci. USA 90:5873-5787 (1993)). One measure of similarity provided by the BLAST algorithm is the smallest sum probability (P(N)), which provides an indication of the probability by which a match between two nucleotide or amino acid sequences would occur by chance. For example, a nucleic acid is considered similar to a reference sequence if the smallest sum probability in a comparison of the test nucleic acid to the reference nucleic acid is less than about 0.2, more preferably less than about 0.01, and most preferably less than about 0.001.

“Conservatively modified variants” applies to both amino acid and nucleic acid sequences. With respect to particular nucleic acid sequences, conservatively modified variants refers to those nucleic acids which encode identical or essentially identical amino acid sequences, or where the nucleic acid does not encode an amino acid sequence, to essentially identical sequences. Because of the degeneracy of the genetic code, a large number of functionally identical nucleic acids encode any given protein. For instance, the codons GCA, GCC, GCG and GCU all encode the amino acid alanine. Thus, at every position where an alanine is specified by a codon, the codon can be altered to any of the corresponding codons described without altering the encoded polypeptide. Such nucleic acid variations are “silent variations,” which are one species of conservatively modified variations. Every nucleic acid sequence herein which encodes a polypeptide also describes every possible silent variation of the nucleic acid. One of skill will recognize that each codon in a nucleic acid (except AUG, which is ordinarily the only codon for methionine) can be modified to yield a functionally identical molecule. Accordingly, each silent variation of a nucleic acid which encodes a polypeptide is implicit in each described sequence.

As to amino acid sequences, one of skill will recognize that individual substitutions, in a nucleic acid, peptide, polypeptide, or protein sequence which alters a single amino acid or a small percentage of amino acids in the encoded sequence is a “conservatively modified variant” where the alteration results in the substitution of an amino acid with a chemically similar amino acid. Conservative substitution tables providing functionally similar amino acids are well known in the art.

The following six groups each contain amino acids that are conservative substitutions for one another:

1) Alanine (A), Serine (S), Threonine (T);

2) Aspartic acid (D), Glutamic acid (E);

3) Asparagine (N), Glutamine (Q);

4) Arginine (R), Lysine (K);

5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); and

6) Phenylalanine (F), Tyrosine (Y), Tryptophan (W).

(see, e.g., Creighton, Proteins (1984)).

An indication that two nucleic acid sequences or polypeptides are substantially identical is that the polypeptide encoded by the first nucleic acid is immunologically cross reactive with the antibodies raised against the polypeptide encoded by the second nucleic acid. Thus, a polypeptide is typically substantially identical to a second polypeptide, for example, where the two peptides differ only by conservative substitutions. Another indication that two nucleic acid sequences are substantially identical is that the two molecules or their complements hybridize to each other under stringent conditions, as described below.

The phrase “selectively (or specifically) hybridizes to” refers to the binding, duplexing, or hybridizing of a molecule only to a particular nucleotide sequence under stringent hybridization conditions when that sequence is present in a complex mixture (e.g., total cellular or library DNA or RNA).

The phrase “stringent hybridization conditions” refers to conditions under which a probe will hybridize to its target subsequence, typically in a complex mixture of nucleic acid, but to no other sequences. Stringent conditions are sequence-dependent and will be different in different circumstances. Longer sequences hybridize specifically at higher temperatures. An extensive guide to the hybridization of nucleic acids is found in Tijssen, Techniques in Biochemistry and Molecular Biology—Hybridization with Nucleic Probes, “Overview of principles of hybridization and the strategy of nucleic acid assays” (1993). Generally, highly stringent conditions are selected to be about 5-10° C. lower than the thermal melting point (T_(m)) for the specific sequence at a defined ionic strength pH. Low stringency conditions are generally selected to be about 15-30° C. below the T_(m). The T_(m) is the temperature (under defined ionic strength, pH, and nucleic concentration) at which 50% of the probes complementary to the target hybridize to the target sequence at equilibrium (as the target sequences are present in excess, at T_(m), 50% of the probes are occupied at equilibrium). Stringent conditions will be those in which the salt concentration is less than about 1.0 M sodium ion, typically about 0.01 to 1.0 M sodium ion concentration (or other salts) at pH 7.0 to 8.3 and the temperature is at least about 30° C. for short probes (e.g., 10 to 50 nucleotides) and at least about 60° C. for long probes (e.g., greater than 50 nucleotides). Stringent conditions may also be achieved with the addition of destabilizing agents such as formamide. For selective or specific hybridization, a positive signal is at least two times background, preferably 10 time background hybridization.

Nucleic acids that do not hybridize to each other under stringent conditions are still substantially identical if the polypeptides which they encode are substantially identical. This occurs, for example, when a copy of a nucleic acid is created using the maximum codon degeneracy permitted by the genetic code. In such cases, the nucleic acids typically hybridize under moderately stringent hybridization conditions.

In the present invention, genomic DNA or cDNA comprising ANT nucleic acids of the invention can be identified in standard Southern blots under stringent conditions using the nucleic acid sequences disclosed here. For the purposes of this disclosure, suitable stringent conditions for such hybridizations are those which include a hybridization in a buffer of 40% formamide, 1 M NaCl, 1% SDS at 37° C., and at least one wash in 0.2×SSC at a temperature of at least about 50° C., usually about 55° C. to about 60° C., for 20 minutes, or equivalent conditions. A positive hybridization is at least twice background. Those of ordinary skill will readily recognize that alternative hybridization and wash conditions can be utilized to provide conditions of similar stringency.

A further indication that two polynucleotides are substantially identical is if the reference sequence, amplified by a pair of oligonucleotide primers, can then be used as a probe under stringent hybridization conditions to isolate the test sequence from a cDNA or genomic library, or to identify the test sequence in, e.g., an RNA gel or DNA gel blot hybridization analysis.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention relates to control of cell proliferation and thus cell number in plants by modulating ANT activity in plants. For example, the invention provides molecular strategies for manipulating plant biomass through controlling the number of cells and size/mass of plant shoot vegetative organs/structures (e.g. leaves, stems and tubers), roots, flowers and floral organs/structures (e.g. bracts, sepals, petals, stamens, carpels, anthers and ovules), seed (including embryo, endospermn, and seed coat) and fruit (the mature ovary) using ANT gene constructs. Thus, by regulating ANT expression transgenic plants with increased or decreased biomass can be produced. In addition, modulating expression of the gene in male or female reproductive organs can lead to sterility through alteration in the pattern of cell proliferation. Thus, male or female sterile transgenic plants can be produced by enhancing or inhibiting ANT gene expression in the appropriate tissues.

Because the ANT gene product most likely functions as a transcription factor (Vergani et al., FEBS Letters. 400:243-246 (1997)), one of skill will recognize that desired phenotypes associated with altered ANT activity can be obtained by mnodulating the expression or activity of ANT-regulated genes. Any of the methods described for increasing or decreasing ANT expression or activity can be used for this purpose.

Increasing ANT Activity or ANT Gene Expression

Any of a number of means well known in the art can be used to increase ANT activity in plants. Enhanced expression is useful, for example, to increase organ size/mass in desired plant organs. Any organ can be targeted, such as shoot vegetative organs/structures (e.g. leaves, stems and tubers), roots, flowers and floral organs/structures (e.g. bracts, sepals, petals, starnens, carpels, anthers and ovules), seed (including embryo, endosperm, and seed coat) and fruit. The beneficial effects of altering ANT activity need not be the direct result of increased cell proliferation. For instance, increased leaf size/mass will lead to an increase in photosynthesis, which will in turn lead to increased yield. Similarly increased mass/size of roots will lead to increased nutrient uptake and increased yield. Increased stem or pedicel thickness can be used to decreases losses due to breakage, e.g. in cereal crops and fruits.

Increased ANT activity or ANT expression can also be used to produce male or female sterile plants. Male or female sterility is important for agriculture and horticulture, particularly in the production of hybrid varieties that have commercially advantageous superior traits. Male or female sterility allows breeders to make hybrid varieties easily by preventing self-pollen contamination in parental plants. Thus, for instance targeting ANT expression in developing anthers will cause male sterility, but not disrupt female organs thus rendering plants female fertile. Prevention of dehiscence is also desirable for commercial cut flowers. For instance, pollination leads to floral senescence, also pollen grains can be allergenic and in some plants (e.g., lilies) can cause stains.

Expression of the ANT gene in transgenic plants can also cause female sterility. Plants constitutively expressing the ANT gene in ovules produce large mature ovules that are sterile, Therefore, introducing female sterility via controlling ANT function can delay senescence of plants and improve vegetative yield and quality of crop and horticulturally important plants. Alternatively, female sterility can result from decreased ANT expression using methods described below for methods of inhibiting ANT activity or gene expression.

Increasing ANT Gene Expression

Isolated sequences prepared as described herein can be used to introduce expression of a particular ANT nucleic acid to increase endogenous gene expression using methods well known to those of skill in the art. Preparation of suitable constructs and means for introducing them into plants are described below.

One of skill will recognize that the polypeptides encoded by the genes of the invention, like other proteins, have different domains that perform different functions. Thus, the gene sequences need not be full length, so long as the desired functional domain of the protein is expressed. The distinguishing features of ANT polypeptides, including the AP2 domain, nuclear localization signal, and transcription activation domains, are discussed in Elliot et al. or Klucher et al. above.

Modified protein chains can also be readily designed utilizing various recombinant DNA techniques well known to those skilled in the art and described in detail, below. For example, the chains can vary from the naturally occurring sequence at the primary structure level by amino acid substitutions, additions, deletions, and the like. These modifications can be used in a number of combinations to produce the final modified protein chain.

Modification of Endogenous ANT Genes

Methods for introducing genetic mutations into plant genes and selecting plants with desired traits are well known. For instance, seeds or other plant material can be treated with a mutagenic chemical substance, according to standard techniques. Such chemical substances include, but are not limited to, the following: diethyl sulfate, ethylene imine, ethyl methanesulfonate and N-nitroso-N-ethylurea. Alternatively, ionizing radiation from sources such as, X-rays or gamma rays can be used.

Alternatively, homologous recombination can be used to induce targeted gene modifications by specifically targeting the ANT gene in vivo (see, generally, Grewal and Klar, Genetics 146: 1221-1238 (1997) and Xu et al., Genes Dev. 10: 2411-2422 (1996)). Homologous recombination has been demonstrated in plants (Puchta et al., Experientia 50: 277-284 (1994), Swoboda et al., EMBO J. 13: 484-489 (1994); Offringa et al., Proc. Natl. Acad. Sci. USA 90: 7346-7350 (1993); and Kempin et al. Nature 389:802-803 (1997)).

In applying homologous recombination technology to the genes of the invention, mutations in selected portions of an ANT gene sequences (including 5′ upstream, 3′ downstream, and intragenic regions) such as those disclosed here are made in vitro and then introduced into the desired plant using standard techniques. Since the efficiency of homologous recombination is known to be dependent on the vectors used, use of dicistronic gene targeting vectors as described by Mountford et al., Proc. Natl. Acad. Sci. USA 91: 4303-4307 (1994); and Vaulont et al., Transgenic Res. 4: 247-255 (1995) are conveniently used to increase the efficiency of selecting for altered ANT gene expression in transgenic plants. The mutated gene will interact with the target wild-type gene in such a way that homologous recombination and targeted replacement of the wild-type gene will occur in transgenic plant cells, resulting in suppression of ANT activity.

Alternatively, oligonucleotides composed of a contiguous stretch of RNA and DNA residues in a duplex conformation with double hairpin caps on the ends can be used. The RNA/DNA sequence is designed to align with the sequence of the target ANT gene and to contain the desired nucleotide change. Introduction of the chimeric oligonucleotide on an extrachromosomal T-DNA plasmid results in efficient and specific ANT gene conversion directed by chimeric molecules in a small number of transformed plant cells. This method is described in Cole-Strauss et al. Science 273:1386-1389 (1996) and Yoon et al. Proc. Natl. Acad. Sci. USA 93: 2071-2076 (1996).

Other Means for Increasing ANT Activity

One method to increase ANT expression is to use “activation mutagenesis” (see, e.g. Hiyashi et al. Science 258:1350-1353 (1992)). In this method an endogenous ANT gene can be modified to be expressed constitutively, ectopically, or excessively by insertion of T-DNA sequences that contain strong/constitutive promoters upstream of the endogenous ANT gene. As explained below, preparation of transgenic plants overexpressing ANT can also be used to increase ANT expression. Activation mutagenesis of the endogenous ANT gene will give the same effect as overexpression of the transgenic ANT nucleic acid in transgenic plants. Alternatively, an endogenous gene encoding an enhancer of ANT activity or expression of the endogenous ANT gene can be modified to be expressed by insertion of T-DNA sequences in a similar manner and ANT activity can be increased.

Another strategy to increase ANT expression can be the use of dominant hyperactive mutants of ANT by expressing modified ANT transgenes. For example expression of modified ANT with a defective domain that is important for interaction with a negative regulator of ANT activity can be used to generate dominant hyperactive ANT proteins. Alternatively, expression of truncated ANT proteins which have only a domain that interacts with a negative regulator can titrate the negative regulator and thereby increase endogenous ANT activity. Use of dominant mutants to hyperactivate target genes is described in Mizukami et al. Plant Cell 8:831-845 (1996).

Inhibition of ANT Activity or Gene Expression

As explained above, ANT activity is important in controlling a number of plant processes through the regulation of cell proliferation. Inhibition of ANT gene expression activity can be used, for instance, to decrease plant organ size/mass or to induce female sterility in plants. In particular, targeted expression of ANT nucleic acids that inhibit endogenous gene expression (e.g., antisense or co-suppression) can be used to inhibit ovule development at early stages and thus induce female sterility. The life span of the transgenic plants can therefore be extended because fertilization (seed formation) can activate and accelerate senescence processes of plants or organs.

Inhibition of ANT gene function can also be used to truncate vegetative growth, resulting in early flowering. Methods that control flowering time are extremely valuable in agriculture to optimize harvesting time as desired. Therefore, by regulating the function of the ANT genes in plants, it is possible to control time of flowering. For instance, acceleration of fertile plant growth can be obtained by expressing ANT antisense RNA during vegetative development to achieve early flowering. Expression of the ANT transgene can then be shut off during reproductive development to get fertile plants.

Inhibition of ANT Gene Expression

The nucleic acid sequences disclosed here can be used to design nucleic acids useful in a number of methods to inhibit ANT or related gene expression in plants. For instance, antisense technology can be conveniently used. To accomplish this, a nucleic acid segment from the desired gene is cloned and operably linked to a promoter such that the antisense strand of RNA will be transcribed. The construct is then transformed into plants and the antisense strand of RNA is produced. In plant cells, it has been suggested that antisense suppression can act at all levels of gene regulation including suppression of RNA translation (see, Bourque Plant Sci. (Limerick) 105: 125-149 (1995); Pantopoulos In Progress in Nucleic Acid Research and Molecular Biology, Vol. 48. Cohn, W. E. and K. Moldave (Ed.). Academic Press, Inc.: San Diego, Calif., USA; London, England, UK. p. 181-238; Heiser et al. Plant Sci. (Shannon) 127: 61-69 (1997)) and by preventing the accumulation of mRNA which encodes the protein of interest, (see, Baulcombe Plant Mol. Bio. 32:79-88 (1996); Prins and Goldbach Arch. Virol. 141: 2259-2276 (1996); Metzlaff et al. Cell 88: 845-854 (1997), Sheehy et al., Proc. Nat. Acad. Sci. USA, 85:8805-8809 (1988), and Hiatt et al., U.S. Pat. No. 4,801,340).

The nucleic acid segment to be introduced generally will be substantially identical to at least a portion of the endogenous ANT gene or genes to be repressed. The sequence, however, need not be perfectly identical to inhibit expression. The vectors of the present invention can be designed such that the inhibitory effect applies to other genes within a family of genes exhibiting identity or substantial identity to the target gene.

For antisense suppression, the introduced sequence also need not be full length relative to either the primary transcription product or fully processed mRNA. Generally, higher identity can be used to compensate for the use of a shorter sequence. Furthermore, the introduced sequence need not have the same intron or exon pattern, and identity of non-coding segments may be equally effective. Normally, a sequence of between about 30 or 40 nucleotides and about full length nucleotides should be used, though a sequence of at least about 100 nucleotides is preferred, a sequence of at least about 200 nucleotides is more preferred, and a sequence of about 500 to about 3500 nucleotides is especially preferred.

A number of gene regions can be targeted to suppress ANT gene expression. The targets can include, for instance, the coding regions, introns, sequences from exon/intron junctions, 5′ or 3′ untranslated regions, and the like.

Another well known method of suppression is sense co-suppression. Introduction of nucleic acid configured in the sense orientation has been recently shown to be an effective means by which to block the transcription of target genes. For an example of the use of this method to modulate expression of endogenous genes (see, Assaad et al. Plant Mol. Bio. 22: 1067-1085 (1993); Flavell Proc. Natl. Acad. Sci. USA 91: 3490-3496 (1994); Stam et al. Annals Bot. 79: 3-12 (1997); Napoli et al., The Plant Cell 2:279-289 (1990); and U.S. Pat. Nos. 5,034,323, 5,231,020, and 5,283,184).

The suppressive effect may occur where the introduced sequence contains no coding sequence per se, but only intron or untranslated sequences homologous to sequences present in the primary transcript of the endogenous sequence. The introduced sequence generally will be substantially identical to the endogenous sequence intended to be repressed. This minimal identity will typically be greater than about 65%, but a higher identity might exert a more effective repression of expression of the endogenous sequences. Substantially greater identity of more than about 80% is preferred, though about 95% to absolute identity would be most preferred. As with antisense regulation, the effect should apply to any other proteins within a similar family of genes exhibiting identity or substantial identity.

For co-suppression, the introduced sequence, needing less than absolute identity, also need not be full length, relative to either the primary transcription product or fully processed mRNA. This may be preferred to avoid concurrent production of some plants which are overexpressers. A higher identity in a shorter than full length sequence compensates for a longer, less identical sequence. Furthermore, the introduced sequence need not have the same intron or exon pattern, and identity of non-coding segments will be equally effective. Normally, a sequence of the size ranges noted above for antisense regulation is used. In addition, the same gene regions noted for antisense regulation can be targeted using co-suppression technologies.

Oligonucleotide-based triple-helix formation can also be used to disrupt ANT gene expression. Triplex DNA can inhibit DNA transcription and replication, generate site-specific mutations, cleave DNA, and induce homologous recombination (see, e.g., Havre and Glazer J. Virology 67:7324-7331 (1993); Scanlon et al. FASEB J. 9:1288-1296 (1995); Giovannangeli et al. Biochemistry 35:10539-10548 (1996); Chan and Glazer J. Mol. Medicine (Berlin) 75: 267-282 (1997)). Triple helix DNAs can be used to target the same sequences identified for antisense regulation.

Catalytic RNA molecules or ribozymes can also be used to inhibit expression of ANT genes. It is possible to design ribozymes that specifically pair with virtually any target RNA and cleave the phosphodiester backbone at a specific location, thereby functionally inactivating the target RNA. In carrying out this cleavage, the ribozyme is not itself altered, and is thus capable of recycling and cleaving other molecules, making it a true enzyme. The inclusion of ribozyme sequences within antisense RNAs confers RNA-cleaving activity upon them, thereby increasing the activity of the constructs. Thus, ribozymes can be used to target the same sequences identified for antisense regulation.

A number of classes of ribozymes have been identified. One class of ribozymes is derived from a number of small circular RNAs which are capable of self-cleavage and replication in plants. The RNAs replicate either alone (viroid RNAs) or with a helper virus (satellite RNAs). Examples include RNAs from avocado sunblotch viroid and the satellite RNAs from tobacco ringspot virus, lucerne transient streak virus, velvet tobacco mottle virus, solanum nodiflorum mottle virus and subterranean clover mottle virus. The design and use of target RNA-specific ribozymes is described in Zhao and Pick, Nature 365:448-451 (1993); Eastham and Ahlering, J. Urology 156:1186-1188 (1996); Sokol and Murray, Transgenic Res. 5:363-371 (1996); Sun et al., Mol. Biotechnology 7:241-251 (1997); and Haseloff et al., Nature, 334:585-591 (1988).

Modification of Endogenous ANT Genes

Methods for introducing genetic mutations described above can also be used to select for plants with decreased ANT expression.

Other Means for Inhibiting ANT Activity

ANT activity may be modulated by eliminating the proteins that are required for ANT cell-specific gene expression. Thus, expression of regulatory proteins and/or the sequences that control ANT gene expression can be modulated using the methods described here.

Another strategy is to inhibit the ability of an ANT protein to interact with itself or with other proteins. This can be achieved, for instance, using antibodies specific to ANT. In this method cell-specific expression of ANT-specific antibodies is used to inactivate functional domains through antibody:antigen recognition (see, Hupp et al. Cell 83:237-245 (1995)). Interference of activity of an ANT interacting protein(s) can be applied in a similar fashion. Alternatively, dominant negative mutants of ANT can be prepared by expressing a transgene that encodes a truncated ANT protein. Use of dominant negative mutants to inactivate target genes in transgenic plants is described in Mizukami et al. Plant Cell 8:831-845 (1996).

Isolation of ANT Nucleic Acids

Generally, the nomenclature and the laboratory procedures in recombinant DNA technology described below are those well known and commonly employed in the art. Standard techniques are used for cloning, DNA and RNA isolation, amplification and purification. Generally enzymatic reactions involving DNA ligase, DNA polymerase, restriction endonucleases and the like are performed according to the manufacturer's specifications. These techniques and various other techniques are generally performed according to Sambrook et al., Molecular Cloning—A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., (1989) or Current Protocols in Molecular Biology Volumes 1-3, John Wiley & Sons, Inc. (1994-1998).

The isolation of ANT nucleic acids may be accomplished by a number of techniques. For instance, oligonucleotide probes based on the sequences disclosed here can be used to identify the desired gene in a cDNA or genomic DNA library. To construct genomic libraries, large segments of genomic DNA are generated by random fragmentation, e.g. using restriction endonucleases, and are ligated with vector DNA to form concatemers that can be packaged into the appropriate vector. To prepare a cDNA library, mRNA is isolated from the desired organ, such as flowers, and a cDNA library which contains the ANT gene transcript is prepared from the mRNA. Alternatively, cDNA may be prepared from mRNA extracted from other tissues in which ANT genes or homologs are expressed.

The cDNA or genomic library can then be screened using a probe based upon the sequence of a cloned ANT gene disclosed here. Probes may be used to hybridize with genomic DNA or cDNA sequences to isolate homologous genes in the same or different plant species. Alternatively, antibodies raised against an ANT polypeptide can be used to screen an mRNA expression library.

Alternatively, the nucleic acids of interest can be amplified from nucleic acid samples using amplification techniques. For instance, polymerase chain reaction (PCR) technology can be used to amplify the sequences of the ANT genes directly from genomic DNA, from cDNA, from genomic libraries or cDNA libraries. PCR and other in vitro amplification methods may also be useful, for example, to clone nucleic acid sequences that code for proteins to be expressed, to make nucleic acids to use as probes for detecting the presence of the desired mRNA in samples, for nucleic acid sequencing, or for other purposes. For a general overview of PCR see PCR Protocols: A Guide to Methods and Applications. (Innis, M, Gelfand, D., Sninsky, J. and White, T., eds.), Academic Press, San Diego (1990). Appropriate primers and probes for identifying ANT sequences from plant tissues are generated from comparisons of the sequences provided here (e.g. SEQ ID NO: 4) and those provided in Klucher et al. and Elliot et al., supra.

Polynucleotides may also be synthesized by well-known techniques as described in the technical literature. See, e.g., Carruthers et al., Cold Spring Harbor Symp. Quant. Biol. 47:411-418 (1982), and Adams et al., J. Am. Chem. Soc. 105:661 (1983). Double stranded DNA fragments may then be obtained either by synthesizing the complementary strand and annealing the strands together under appropriate conditions, or by adding the complementary strand using DNA polymerase with an appropriate primer sequence. Because at the very 5′ and 3′ ends the Arabidopsis ANT nucleotide sequence is very similar to the Brassica ANT nucleotide sequence but not to other Arabidopsis AP2-domain containing genes, the primers with nucleotide sequences shown in SEQ ID NO:6, SEQ ID NO:7, or SEQ ID NO:8 can be used to screen/isolate ANT orthologs in different species by RT-PCR.

Preparation of Recombinant Vectors

To use isolated sequences in the above techniques, recombinant DNA vectors suitable for transformation of plant cells are prepared. Techniques for transforming a wide variety of higher plant species are well known and described in the technical and scientific literature. See, for example, Weising et al. Ann. Rev. Genet. 22:421-477 (1988). A DNA sequence coding for the desired polypeptide, for example a cDNA sequence encoding a full length protein, will preferably be combined with transcriptional and translational initiation regulatory sequences which will direct the transcription of the sequence from the gene in the intended tissues of the transformed plant.

For example, for overexpression, a plant promoter fragment may be employed which will direct expression of the gene in all tissues of a regenerated plant. Such promoters are referred to herein as “constitutive” promoters and are active under most environmental conditions and states of development or cell differentiation. Examples of constitutive promoters include the cauliflower mosaic virus (CaMV) 35S transcription initiation region, the 1′- or 2′-promoter derived from T-DNA of Agrobacterium tumafaciens, and other transcription initiation regions from various plant genes known to those of skill. Such genes include for example, ACT11 from Arabidopsis (Huang et al. Plant Mol. Biol. 33:125-139 (1996)), Cat3 from Arabidopsis (GenBank No. U43147, Zhong et al., Mol. Gen. Genet. 251:196-203 (1996)), the gene encoding stearoyl-acyl carrier protein desaturase from Brassica napus (Genbank No. X74782, Solocombe et al. Plant Physiol. 104:1167-1176 (1994)), GPc1 from maize (GenBank No. X15596, Martinez et al. J. Mol. Biol 208:551-565 (1989)), and Gpc2 from maize (GenBank No. U45855, Manjunath et al., Plant Mol. Biol. 33:97-112 (1997)).

Alternatively, the plant promoter may direct expression of the ANT nucleic acid in a specific tissue, organ or cell type (i.e. tissue-specific promoters) or may be otherwise under more precise environmental or developmental control (i.e. inducible promoters). Examples of environmental conditions that may effect transcription by inducible promoters include anaerobic conditions, elevated temperature, the presence of light, or sprayed with chemicals/hormones. One of skill will recognize that a tissue-specific promoter may drive expression of operably linked sequences in tissues other than the target tissue. Thus, as used herein a tissue-specific promoter is one that drives expression preferentially in the target tissue or cell type, but may also lead to some expression in other tissues as well.

A number of tissue-specific promoters can also be used in the invention. For instance, promoters that direct expression of nucleic acids in flowers, ovules, or anthers (particularly the tapetum) are useful in methods in which sterility is desired. An example of a promoter that directs expression in the ovule is the promoter from the BEL1 gene described in Reiser et al. Cell 83:735-742 (1995) (GenBank No. U39944). Examples of tapetal-specific promoters include TA29 from tobacco (Mariani et al., Nature, 347:737-41, (1990)), and A6 and A9 from Brassica (Paul et al., Plant Mol. Biol., 19:611-22, (1992), Hird et al. Plant Journal 4:1023-1033 (1993)). Anther-specific promoters could also be used such as ones isolated by Twell et al. (Mol. Gen. Genet., 217:240-45, (1991)).

To introduce male sterility, the 2nd and 3rd floral organ (petal and stamens)-specific AP3 promoter (Day, et al., Development 121:2887, 1995), for example, can be used. The carpel specific AGL1 (Flanagan and Ma, Plant J. 10:343, 1993) or AGL5 (Savidge, et al., Plant Cell 7:721, 1995) promoter can be applied for inducing female sterility only. Sterile plants, yet with increased perianth organs, can be obtained by constitutively expressing the ANT gene through AG promoter (Sieburth and Meyerowitz, Plant Cell 9:355, 1997) that is active only in reproductive organ primordia and developing male and female organs.

Using the AP1 promoter (Gustafson-Brown, et al., Cell 76:131, 1994) that is expressed in floral primordia at early stages of flower development and in developing perianth organs, fertile flowers with enlarged perianth organs can be produced. For the increase of aerial vegetative organ biomass, photosynthetic organ-specific promoters, such as the RBCS promoter (Khoudi, et al., Gene 197:343, 1997), can be used. Root biomass can be increased by the constitutive ANT expression under the control of the root-specific ANR1 promoter (Zhang & Forde, Science, 279:407, 1998). To increase seed size/mass (an agronomically import trait), seed-specific promoters, such as the LEC promoter (Lotan, et al., Cell 93:1195 (1998)), the late-embroygenesis-abundant promoter (West et al. Plant Cell 6:173 (1994)), beta-conglycininin alpha-subunit promoter (West et al.), the lectin promoter (Goldberg et al. Science 266:605 (1994)), or the Kunitz trypsin inhibitor 3 promoter (Goldberg et al.) can be used. Any strong, constitutive promoters, such as the CaMV 35S promoter, can be used for the increase of total plant biomass.

If proper polypeptide expression is desired, a polyadenylation region at the 3′-end of the coding region should be included. The polyadenylation region can be derived from the natural gene, from a variety of other plant genes, or from T-DNA.

The vector comprising the sequences (e.g., promoters or coding regions) from genes of the invention will typically comprise a marker gene that confers a selectable phenotype on plant cells. For example, the marker may encode biocide resistance, particularly antibiotic resistance, such as resistance to kanamycin, G418, bleomycin, hygromycin, or herbicide resistance, such as resistance to chlorosulfuron or Basta.

The present invention also provides promoter sequences from the ANT gene (SEQ ID NO:3), which can be used to direct expression of the ANT coding sequence or heterologous sequences in desired tissues. ANT is expressed in meristematic cells throughout the plant. ANT promoter sequences of the invention are therefore useful in targeting expression to meristematic cells in lateral roots, leaf primordia, developing leaves, floral primordia, floral organ primordia, developing floral organs, ovule primordia, developing ovules, developing embryos, and vascular systems. Genes whose expression can be targeted to these cells in immature organs include disease resistance genes, such as the Arabidopsis NPR1 gene (Cao, et al., Cell 88:57, 1997) and the nematode resistance locus Gro1 and the Phytophthora infestans resistance locus R7 of potato (Leister, et al., Nature Genetics 14:421, 1996), for increasing resistance to pathogens and insects in young, sensitive organs.

Because the ANT promoter is expressed in developing embryos at late stages, some genes encoding regulators or key enzymes for biosynthesis of storage oils, proteins, or starches, such as BiP (Hatano, et al., Plant and Cell Physiology 38:344, 1997), can be expressed by the control of the ANT promoter.

Production of Transgenic Plants

DNA constructs of the invention may be introduced into the genome of the desired plant host by a variety of conventional techniques. For example, the DNA construct may be introduced directly into the genomic DNA of the plant cell using techniques such as electroporation and microinjection of plant cell protoplasts, or the DNA constructs can be introduced directly to plant tissue using ballistic methods, such as DNA particle bombardment.

Microinjection techniques are known in the art and well described in the scientific and patent literature. The introduction of DNA constructs using polyethylene glycol precipitation is described in Paszkowski et al. Embo J. 3:2717-2722 (1984). Electroporation techniques are described in Fromm et al. Proc. Natl. Acad. Sci. USA 82:5824 (1985). Ballistic transformation techniques are described in Klein et al. Nature 327:70-73 (1987).

Alternatively, the DNA constructs may be combined with suitable T-DNA flanking regions and introduced into a conventional Agrobacterium tumefaciens host vector. The virulence functions of the Agrobacterium tumefaciens host will direct the insertion of the construct and adjacent marker into the plant cell DNA when the cell is infected by the bacteria. Agrobacterium tumefaciens-mediated transformation techniques, including disarming and use of binary vectors, are well described in the scientific literature. See, for example Horsch et al. Science 233:496-498 (1984), and Fraley et al. Proc. Natl. Acad. Sci. USA 80:4803 (1983) and Gene Transfer to Plants, Potrykus, ed. (Springer-Verlag, Berlin 1995).

Transformed plant cells which are derived by any of the above transformation techniques can be cultured to regenerate a whole plant which possesses the transformed genotype and thus the desired phenotype such as increased seed mass. Such regeneration techniques rely on manipulation of certain phytohormones in a tissue culture growth medium, typically relying on a biocide and/or herbicide marker that has been introduced together with the desired nucleotide sequences. Plant regeneration from cultured protoplasts is described in Evans et al., Protoplasts Isolation and Culture, Handbook of Plant Cell Culture, pp. 124-176, MacMillilan Publishing Company, New York, 1983; and Binding, Regeneration of Plants, Plant Protoplasts, pp. 21-73, CRC Press, Boca Raton, 1985. Regeneration can also be obtained from plant callus, explants, organs, or parts thereof. Such regeneration techniques are described generally in Klee et al. Ann. Rev. of Plant Phys. 38:467-486 (1987).

The nucleic acids of the invention can be used to confer desired traits on essentially any plant. Thus, the invention has use over a broad range of plants, including species from the genera Anacardium, Arachis, Asparagus, Atropa, Avena, Brassica, Chlamydomonas, Chlorella, Citrus, Citrullus, Capsicum, Carthamus, Cocos, Coffea, Cucumis, Cucurbita, Cyrtomium, Daucus, Elaeis, Fragaria, Glycine, Gossypium, Helianthus, Heterocallis, Hordeum, Hyoscyamus, Lactuca, Laminaria, Linum, Lolium, Lupinus, Lycopersicon, Macrocystis, Malus, Manihot, Majorana, Medicago, Nereocystis, Nicotiana, Olea, Oryza, Osmunda, Panieum, Pannesetum, Persea, Phaseolus, Pistachia, Pisum, Pyrus, Polypodium, Prunus, Pteridium, Raphanus, Ricinus, Secale, Senecio, Sinapis, Solanum, Sorghum, Theobromus, Trigonella, Triticum, Vicia, Vitis, Vigna, and Zea.

One of skill will recognize that after the expression cassette is stably incorporated in transgenic plants and confirmed to be operable, it can be introduced into other plants by sexual crossing. Any of a number of standard breeding techniques can be used, depending upon the species to be crossed.

Using known procedures one of skill can screen for plants of the invention by detecting the increase or decrease of ANT mRNA or protein in transgenic plants. Means for detecting and quantitating mRNAs or proteins are well known in the art. The plants of the invention can also be identified by detecting the desired phenotype. For instance, increased biomass of organs or plants can be detected according to well-known techniques. Male or female sterility can be identified by testing for viable pollen and/or the ability to set seed.

The following Examples are offered by way of illustration, not limitation.

EXAMPLE 1

This example shows that increased ANT expression increases cell number and the size/mass of roots, leaves, floral organs, ovules and seeds in Arabidopsis.

An ANT cDNA with a BamHI site right before the initiation codon of the ANT coding nucleotide sequence was created by PCR using synthetic oligonucleotide primers. This ANT nucleic acid (from C at 268 to T at 2148 (1881 nucleotides) from SEQ ID NO: 1) was ligated at the BglII site of the plasmid vector pMON530 (Rogers, et al., Meth. Enzymol. 153:253, 1987) under the constitutive 35S promoter, and the recombinant plasmid DNA which has an insert of the ANT cDNA in the sense direction with respect to the CaMV 35S promoter (35S::ANT) were selected. Agrobacterium cells were transformed with the recombinant plasmid DNA, and used for Agrobacterium-mediated plant transformation by vacuum infiltration with Arabidopsis plants (Col-0 ecotype). T₁ seeds were collected from transformed plants about three weeks after vacuum infiltration, and planted on MS plates with kanamycin for screening T₁ transgenic seedlings.

T₁ seeds include oversized seeds, which were distinguished because they did not pass through a mesh of defined size. The majority of these seeds were kanamycin resistant, carrying the 35S::ANT transgene. This phenotype was not observed in vector only controls.

Multiple T₁ seedlings were larger than vector only control transgenic seedlings. As they develop, T₁ plants produced a highly branched root system having a larger mass than vector only controls. In addition, the plants had enlarged leaves, floral organs, and ovules as compared to the vector only controls. For example, the average flower and leaf biomass of T₁ lines was approximately three times and 2.5 times that of the vector only control, respectively. DIC microscopy and scanning electron microscopy revealed that this enlarged organ phenotype of T₁ plants was due to the increased cell number in the organs. In addition, T₁ plants were sterile. Preliminary examination suggests that anthers fail to shed pollen (which are morphologically normal) and the ovules were unusually large with an increased number of nucellar cells that compress/displace the female gametophyte.

Because sterility made it difficult to generate and propagate homozygous transgenic lines, we used a chemical induction system as described by Aoyama, and Chua Plant J. 11:605-612 (1997) and McNellis et al. Plant J. 14:247-257 (1998) to regulate ectopic ANT transcription. This system utilizes a chimeric transcription factor gene (35S::GVG), consisting of the 35S promoter, the DNA-binding domain of the yeast transcription factor GAL4, a transactivating domain, and the receptor domain of the glucocorticoid receptor (GR). The ANT gene was inserted downstream from a promoter (UAS::ANT) containing the binding site for the GVG transcription factor. The 35S::GVG/UAS::ANT construct was introduced into wild-type Arabidopsis and fertile transgenic lines were obtained generally as described above.

Transgenic T₂ plants were germinated on MS agar plates and transferred to plates either with or without the chemical inducer, dexamethasone (DEX), a synthetic glucocorticoid hormone that binds and activates the GVG transcription factor. Multiple transgenic lines were obtained that displayed an enlarged leaf phenotype after treatment with DEX. The increase in organ size/mass is due to an increased number of cells. DEX had no effect on control transgenic plants with only the 35S::GVG/UAS vector. Taken together, these results suggest that ectopic ANT expression increases organ size/mass by increasing cell number.

EXAMPLE 2

This example shows that essentially the same phenotypic changes observed in Arabidopsis were observed in tobacco.

For generating tobacco transgenic plants expressing ANT cDNA under the control of the constitutive 35S promoter, the above recombinant plasmid DNA was used for Agrobacterium-mediated tobacco callus transformation. Tobacco calli were induced from sterilized tobacco leaf (S1 variety) placed on callus-inducing plates, then co-cultivated with Agrobacterium cells carrying the above recombinant DNA for three days. After washing bacterial cells out, leaf calli were placed on shoot-inducing agar plate containing kanamycin and carbenicillin to generate transformed shoots. These R₀ shoots were transferred on root inducing agar plates, then transplanted on soil after regeneration of roots.

The R₀ plants in which the ANT gene was constitutively expressed under the control of the CaMV 35S promoter produced wider leaves (about 1.5 times that of vector only control transgenic plants), relatively larger flowers (about 1.7 time greater mass than vector only control transgenic plants), and sterility as observed with Arabidopsis. The sterility is largely caused by the failure of dehiscence of anthers as seen in the Arabidopsis transgenic anthers. Some R₀ plants produced functional pollen grains in their closed anthers, and produced seeds (R₁ seeds) upon self-pollination by hand using pollen grains dissected from the anther. These R₁ seeds had mass about 1.5 times that of seed from vector only control plants.

EXAMPLE 3

This example describes plant organ size/mass reduction and altered flowering by co-suppressing endogenous gene activity by the ANT transgene in Arabidopsis and tobacco.

Arabidopsis T₁ lines described above included lines exhibiting reduced organ size/mass and organ cell numbers. These plants were completely or partially female sterile, as are loss-of-function ant mutants. In these lines, expression of ANT mRNA was highly reduced, suggesting that co-suppression of the endogenous ANT gene, as well as that of the ANT cDNA, took place in the lines. From partially sterile T₁ lines, transgenic T₂ plants were obtained that segregated for the same co-suppressed phenotype as in T₁ parental plants. Reduction of organ size/mass was also observed in co-suppressed R₀ tobacco plants.

Multiple co-suppressed lines also exhibited early flowering. Plants of these lines displayed reduced numbers of rosette leaves and fewer days before bolting. Because early-flowering phenotype was not observed in loss-of-function ant mutants, co-suppression by the ANT transgene could also influence other unknown ANT related genes that regulate flowering time by itself or together with ANT. Similar results were also observed in co-suppressed transgenic tobacco plants.

EXAMPLE 4

This example shows the isolation of an ANT ortholog from Brassica napus (Canola).

The nucleic acid sequence and the encoded protein of the Brassica cDNA are shown in SEQ ID NO: 4 and SEQ ID NO:5 respectively.

To prepare this nucleic acid, total RNA was isolated from young shoot apices of Brassica napus (Canola) seedlings using TRIZOL as described by Colasanti et al. (Cell. 93:593-603 (1998)). cDNA was made by reverse transcription, and amplified by PCR using the high fidelity thermo-tolerant DNA polymerase PFU and oligonucleotide primers. The primers had the initiation codon and the anti-parallel nucleotide sequence downstream of the stop codon of the Arabidopsis ANT nucleotide sequence, respectively. The PCR products were subcloned into an E. coli vector and screened by PCR using different sets of oligonucleotide primers having internal ANT nucleotide sequence. Nucleotide sequence of the inserted Brassica DNA of selected recombinant plasmid clones was determined and compared to the Arabidopsis ANT nucleotide sequence for confirmation. The Brassica ANT (BANT) gene shares 85.5% identity to the Arabidopsis ANT gene in their coding region at the nucleotide level and the BANT polypeptide sequence is 83.7% identical to the ANT polypeptide sequence, respectively.

EXAMPLE 5

This example shows use of the ANT 5′-upstream nucleotide sequence (promoter) for expressing heterologous genes in meristematic cells.

A HindIII-BglII fragment which includes the correctly oriented ANT promoter was inserted into the pBI101 plasmid vector DNA (CLONTECH) at the HindIII and BamHI sites which are located right before the initiation codon of the GUS (beta-glucuronidase) gene. The same fragment was also inserted into the plasmid pBIN m-gfp5-ER (Haseloff, et al., Proc. Natl. Acad. Sci. U.S.A. 94:2122-2127, (1997) at the HindIII-BamHI sites located immediately before the initiation codon of the GFP (green fluorescence protein) gene. Arabidopsis wild-type plants were transformed by these recombinant plasmids using the Agrobacterium-mediated vacuum infiltration method. Multiple T₁ lines, and their following generations, exhibited GUS activity or GFP expression in meristematic cells throughout plant development as expected, proving that the ANT promoter is useful for expressing a heterologous gene in meristematic cells.

EXAMPLE 6

This example shows activation of the cyclin D3 (CYCD3) gene expression by increasing ANT gene expression in Arabidopsis plants.

Cell proliferation is directly controlled by the activity of cell cycle regulatory genes, such as cyclins and cdks (Nasmyth, Trends Genet., 12:405-412, (1996); Morgan, Nature, 374:131-134, 1995; and Burssens, et al., Plant Physiol. Biochem., 36:9-19, (1998)). Because organs from T₁ transgenic lines in which ANT gene expression is controlled by the CaMV 35S promoter had increased number of cells, and thus increased cell proliferation activity, expression of cyclin genes in young and mature organs of T₁ plants was measured by quantitative RT-PCR analysis. In young developing organs, where cell proliferation was observed in both 35S::ANT and control plants, the difference of expression levels of cyclin genes between them were not significant. However, in mature organs, while mRNA accumulation of CYCD3, which encodes a key regulator for G1/S entry in the Arabidopsis cell cycle (Soni, et al., Plant Cell. 7:85-103 (1995); Fuerst, et al., Plant Physiol. 112:1023-1033 (1996), is no longer detected in control, it was detected in 35S::ANT lines. These results agree with observations that no growth differences were detected at early stages of organ development between 35S::ANT lines and control lines; however, when organs of control plants were mature and ceased cell proliferation, cells in the same aged organs of 35S::ANT plants continued to proliferate and give rise to enlarged organs as the result.

This result demonstrates that the increased constitutive ANT activity directly and/or indirectly controls the cell cycle machinery via regulating expression of a cell cycle regulator gene(s) and continuously activating cell proliferation in developing organs. This also indicates that certain genes involved in cell cycle machinery are targets of the ANT transcription factor gene (Klucher et al. and Elliot et al.). Taken together, these results suggest that modulation of expression of these ANT-target genes could regulate organ size/mass and fertility in plants.

The above examples are provided to illustrate the invention but not to limit its scope. Other variants of the invention will be readily apparent to one of ordinary skill in the art and are encompassed by the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference for all purposes.

8 1 2148 DNA Arabidopsis thaliana CDS (269)..(1936) AINTEGUMENTA (ANT) 1 agatcccaac ggattcaaac agcaaatttg tgctttgctc ttctctctta ttataatatc 60 ctctcaaaaa ccctctccta tatcctccta aagcccccct tccttgtttc tctaccgcaa 120 caaagaaaaa acaaaagttt gagaaaaatg gtgtgttcgt tgtgtaacca atgattgggt 180 tttagcttac tacttcgaga gattataaga aagaaagagt gaagatacat tatagaaaga 240 agagaagcag aaaccaaaaa aagaaacc atg aag tct ttt tgt gat aat gat 292 Met Lys Ser Phe Cys Asp Asn Asp 1 5 gat aat aat cat agc aac acg act aat ttg tta ggg ttc tca ttg tct 340 Asp Asn Asn His Ser Asn Thr Thr Asn Leu Leu Gly Phe Ser Leu Ser 10 15 20 tca aat atg atg aaa atg gga ggt aga gga ggt aga gaa gct att tac 388 Ser Asn Met Met Lys Met Gly Gly Arg Gly Gly Arg Glu Ala Ile Tyr 25 30 35 40 tca tct tca act tct tca gct gca act tct tct tct tct gtt cca cct 436 Ser Ser Ser Thr Ser Ser Ala Ala Thr Ser Ser Ser Ser Val Pro Pro 45 50 55 caa ctt gtt gtt ggt gac aac act agc aac ttt ggt gtt tgc tat gga 484 Gln Leu Val Val Gly Asp Asn Thr Ser Asn Phe Gly Val Cys Tyr Gly 60 65 70 tct aac cca aat gga gga atc tat tct cac atg tct gtg atg cca ctc 532 Ser Asn Pro Asn Gly Gly Ile Tyr Ser His Met Ser Val Met Pro Leu 75 80 85 aga tct gat ggt tct ctt tgc tta atg gaa gct ctc aac aga tct tct 580 Arg Ser Asp Gly Ser Leu Cys Leu Met Glu Ala Leu Asn Arg Ser Ser 90 95 100 cac tcg aat cac cat caa gat tca tct cca aag gtg gag gat ttc ttt 628 His Ser Asn His His Gln Asp Ser Ser Pro Lys Val Glu Asp Phe Phe 105 110 115 120 ggg acc cat cac aac aac aca agt cac aaa gaa gcc atg gat ctt agc 676 Gly Thr His His Asn Asn Thr Ser His Lys Glu Ala Met Asp Leu Ser 125 130 135 tta gat agt tta ttc tac aac acc act cat gag ccc aac acg act aca 724 Leu Asp Ser Leu Phe Tyr Asn Thr Thr His Glu Pro Asn Thr Thr Thr 140 145 150 aac ttt caa gag ttc ttt agc ttc cct caa acc aga aac cat gag gaa 772 Asn Phe Gln Glu Phe Phe Ser Phe Pro Gln Thr Arg Asn His Glu Glu 155 160 165 gaa act aga aat tac ggg aat gac cct agt ttg aca cat gga ggg tct 820 Glu Thr Arg Asn Tyr Gly Asn Asp Pro Ser Leu Thr His Gly Gly Ser 170 175 180 ttt aat gta ggg gta tat ggg gaa ttt caa cag tca ctg agc tta tcc 868 Phe Asn Val Gly Val Tyr Gly Glu Phe Gln Gln Ser Leu Ser Leu Ser 185 190 195 200 atg agc cct ggg tca caa tct agc tgc atc act ggc tct cac cac cac 916 Met Ser Pro Gly Ser Gln Ser Ser Cys Ile Thr Gly Ser His His His 205 210 215 caa caa aac caa aac caa aac cac caa agc caa aac cac cag cag atc 964 Gln Gln Asn Gln Asn Gln Asn His Gln Ser Gln Asn His Gln Gln Ile 220 225 230 tct gaa gct ctt gtg gag aca agc gtt ggg ttt gag acg acg aca atg 1012 Ser Glu Ala Leu Val Glu Thr Ser Val Gly Phe Glu Thr Thr Thr Met 235 240 245 gcg gct gcg aag aag aag agg gga caa gag gat gtt gta gtt gtt ggt 1060 Ala Ala Ala Lys Lys Lys Arg Gly Gln Glu Asp Val Val Val Val Gly 250 255 260 cag aaa cag att gtt cat aga aaa tct atc gat act ttt gga caa cga 1108 Gln Lys Gln Ile Val His Arg Lys Ser Ile Asp Thr Phe Gly Gln Arg 265 270 275 280 act tct caa tac cga ggc gtt aca aga cat aga tgg act ggt aga tat 1156 Thr Ser Gln Tyr Arg Gly Val Thr Arg His Arg Trp Thr Gly Arg Tyr 285 290 295 gaa gct cat cta tgg gac aat agt ttc aag aag gaa ggt cac agt aga 1204 Glu Ala His Leu Trp Asp Asn Ser Phe Lys Lys Glu Gly His Ser Arg 300 305 310 aaa gga aga caa gtt tat ctg gga ggt tat gat atg gag gag aaa gct 1252 Lys Gly Arg Gln Val Tyr Leu Gly Gly Tyr Asp Met Glu Glu Lys Ala 315 320 325 gct cga gca tat gat ctt gct gca ctc aag tac tgg ggt ccc tct act 1300 Ala Arg Ala Tyr Asp Leu Ala Ala Leu Lys Tyr Trp Gly Pro Ser Thr 330 335 340 cac acc aat ttc tct gcg gag aat tat cag aaa gag att gaa gac atg 1348 His Thr Asn Phe Ser Ala Glu Asn Tyr Gln Lys Glu Ile Glu Asp Met 345 350 355 360 aag aac atg act aga caa gaa tat gtt gca cat ttg aga agg aag agc 1396 Lys Asn Met Thr Arg Gln Glu Tyr Val Ala His Leu Arg Arg Lys Ser 365 370 375 agt ggt ttc tct agg ggt gct tcc atc tat aga gga gtc aca aga cat 1444 Ser Gly Phe Ser Arg Gly Ala Ser Ile Tyr Arg Gly Val Thr Arg His 380 385 390 cac cag cat gga agg tgg caa gca cgg att ggt aga gtc gct gga aac 1492 His Gln His Gly Arg Trp Gln Ala Arg Ile Gly Arg Val Ala Gly Asn 395 400 405 aaa gat ctc tac ctt gga act ttt gga acc caa gaa gaa gct gca gaa 1540 Lys Asp Leu Tyr Leu Gly Thr Phe Gly Thr Gln Glu Glu Ala Ala Glu 410 415 420 gct tac gat gta gca gca att aag ttc cgt ggc aca aat gct gtg act 1588 Ala Tyr Asp Val Ala Ala Ile Lys Phe Arg Gly Thr Asn Ala Val Thr 425 430 435 440 aac ttt gat atc acg agg tac gat gtt gat cgt atc atg tct agt aac 1636 Asn Phe Asp Ile Thr Arg Tyr Asp Val Asp Arg Ile Met Ser Ser Asn 445 450 455 aca ctc ttg tct gga gag tta gcg cga agg aac aac aac agc att gtc 1684 Thr Leu Leu Ser Gly Glu Leu Ala Arg Arg Asn Asn Asn Ser Ile Val 460 465 470 gtc agg aat act gaa gac caa acc gct cta aat gct gtt gtg gaa ggt 1732 Val Arg Asn Thr Glu Asp Gln Thr Ala Leu Asn Ala Val Val Glu Gly 475 480 485 ggt tcc aac aaa gaa gtc agt act ccc gag aga ctc ttg agt ttt ccg 1780 Gly Ser Asn Lys Glu Val Ser Thr Pro Glu Arg Leu Leu Ser Phe Pro 490 495 500 gcg att ttc gcg ttg cct caa gtt aat caa aag atg ttc gga tca aat 1828 Ala Ile Phe Ala Leu Pro Gln Val Asn Gln Lys Met Phe Gly Ser Asn 505 510 515 520 atg ggc gga aat atg agt cct tgg aca tca aac cct aat gct gag ctt 1876 Met Gly Gly Asn Met Ser Pro Trp Thr Ser Asn Pro Asn Ala Glu Leu 525 530 535 aag acc gtc gct ctt act ttg cct cag atg ccg gtt ttc gct gct tgg 1924 Lys Thr Val Ala Leu Thr Leu Pro Gln Met Pro Val Phe Ala Ala Trp 540 545 550 gct gat tct tgatcaactt caatgactaa ctctggtttt cttggtttag 1973 Ala Asp Ser 555 ttgctaagtg ttttggttta tctccggttt tatccggttt gaactacaat tcggtttagt 2033 ttcgtcggta taaatagtat ttgcttagga gcggtatatg tttcttttga gtagtattca 2093 tgtgaaacag aatgaatctc tctataacat attattttaa tgaatctcct ttgct 2148 2 555 PRT Arabidopsis thaliana 2 Met Lys Ser Phe Cys Asp Asn Asp Asp Asn Asn His Ser Asn Thr Thr 1 5 10 15 Asn Leu Leu Gly Phe Ser Leu Ser Ser Asn Met Met Lys Met Gly Gly 20 25 30 Arg Gly Gly Arg Glu Ala Ile Tyr Ser Ser Ser Thr Ser Ser Ala Ala 35 40 45 Thr Ser Ser Ser Ser Val Pro Pro Gln Leu Val Val Gly Asp Asn Thr 50 55 60 Ser Asn Phe Gly Val Cys Tyr Gly Ser Asn Pro Asn Gly Gly Ile Tyr 65 70 75 80 Ser His Met Ser Val Met Pro Leu Arg Ser Asp Gly Ser Leu Cys Leu 85 90 95 Met Glu Ala Leu Asn Arg Ser Ser His Ser Asn His His Gln Asp Ser 100 105 110 Ser Pro Lys Val Glu Asp Phe Phe Gly Thr His His Asn Asn Thr Ser 115 120 125 His Lys Glu Ala Met Asp Leu Ser Leu Asp Ser Leu Phe Tyr Asn Thr 130 135 140 Thr His Glu Pro Asn Thr Thr Thr Asn Phe Gln Glu Phe Phe Ser Phe 145 150 155 160 Pro Gln Thr Arg Asn His Glu Glu Glu Thr Arg Asn Tyr Gly Asn Asp 165 170 175 Pro Ser Leu Thr His Gly Gly Ser Phe Asn Val Gly Val Tyr Gly Glu 180 185 190 Phe Gln Gln Ser Leu Ser Leu Ser Met Ser Pro Gly Ser Gln Ser Ser 195 200 205 Cys Ile Thr Gly Ser His His His Gln Gln Asn Gln Asn Gln Asn His 210 215 220 Gln Ser Gln Asn His Gln Gln Ile Ser Glu Ala Leu Val Glu Thr Ser 225 230 235 240 Val Gly Phe Glu Thr Thr Thr Met Ala Ala Ala Lys Lys Lys Arg Gly 245 250 255 Gln Glu Asp Val Val Val Val Gly Gln Lys Gln Ile Val His Arg Lys 260 265 270 Ser Ile Asp Thr Phe Gly Gln Arg Thr Ser Gln Tyr Arg Gly Val Thr 275 280 285 Arg His Arg Trp Thr Gly Arg Tyr Glu Ala His Leu Trp Asp Asn Ser 290 295 300 Phe Lys Lys Glu Gly His Ser Arg Lys Gly Arg Gln Val Tyr Leu Gly 305 310 315 320 Gly Tyr Asp Met Glu Glu Lys Ala Ala Arg Ala Tyr Asp Leu Ala Ala 325 330 335 Leu Lys Tyr Trp Gly Pro Ser Thr His Thr Asn Phe Ser Ala Glu Asn 340 345 350 Tyr Gln Lys Glu Ile Glu Asp Met Lys Asn Met Thr Arg Gln Glu Tyr 355 360 365 Val Ala His Leu Arg Arg Lys Ser Ser Gly Phe Ser Arg Gly Ala Ser 370 375 380 Ile Tyr Arg Gly Val Thr Arg His His Gln His Gly Arg Trp Gln Ala 385 390 395 400 Arg Ile Gly Arg Val Ala Gly Asn Lys Asp Leu Tyr Leu Gly Thr Phe 405 410 415 Gly Thr Gln Glu Glu Ala Ala Glu Ala Tyr Asp Val Ala Ala Ile Lys 420 425 430 Phe Arg Gly Thr Asn Ala Val Thr Asn Phe Asp Ile Thr Arg Tyr Asp 435 440 445 Val Asp Arg Ile Met Ser Ser Asn Thr Leu Leu Ser Gly Glu Leu Ala 450 455 460 Arg Arg Asn Asn Asn Ser Ile Val Val Arg Asn Thr Glu Asp Gln Thr 465 470 475 480 Ala Leu Asn Ala Val Val Glu Gly Gly Ser Asn Lys Glu Val Ser Thr 485 490 495 Pro Glu Arg Leu Leu Ser Phe Pro Ala Ile Phe Ala Leu Pro Gln Val 500 505 510 Asn Gln Lys Met Phe Gly Ser Asn Met Gly Gly Asn Met Ser Pro Trp 515 520 525 Thr Ser Asn Pro Asn Ala Glu Leu Lys Thr Val Ala Leu Thr Leu Pro 530 535 540 Gln Met Pro Val Phe Ala Ala Trp Ala Asp Ser 545 550 555 3 4228 DNA Arabidopsis thaliana promoter (1)..(4228) ANT promoter 3 gtcgactcta ggcctcactg gcctaatacg actcactata gggagctcga ggatccttta 60 gttagaaaaa actttctttg tacgtgtgtg tgtgtgtttt aagttcaatt ataactagtc 120 acatgtgata tcacaatata tatattgaaa ttggaattat tcatattaat gagttagcat 180 taatatatat acgctgacat taccaaccaa atgtttctgc ttttatggat agttctatat 240 gttgcacttg attatagata ctatataaaa ctgggtttat ttaaaatccg tacccataac 300 aaaagtggac caaaacgaga tccatggttt tgtgtttact ttgttggtta accagataat 360 atgattatgg aagattaaat ctttactaaa ttataaaata atttggaaaa acaaacttaa 420 atatgttgag tgtcttcagt gctcactgtt caagaataat ctcgtgttat cctacttgaa 480 ctagaagttg atatacataa acacgtgaat attttaacga ccgtacataa acacatgtat 540 cgatcaaata caaattatta tgagactaga atccaagatg aggatgactc tagcagaata 600 tacacagcta agaatttgta caagagagtc gaaaaataga ttctaatcat ttaaaaaaga 660 tatggatttc agttacggat tgatattacc attacgcagt agtacataca cataattttt 720 tgtttttgtt ttaccgataa tagaatgaaa atgttgtgtt aaaaatattg gttttactaa 780 aactcgtttt atgttaacta tataatgtct ttccgcatgt aaattgaaac aaaactgtaa 840 tacaaattat gttaagccat tgcaattaaa aaatccacgg gtagtaaatc ctcagaagat 900 tatgttaagt ctacaaattt tctctttaga ttagtaaggt ttgagacaaa attatgtata 960 ccttgcaggg gtataaaggt cactgcatag tcagactcag catgaagcca aagagtcgtc 1020 tctgtcctaa agatatctac agctgcttcg cctgtgaata gagaagaaat tgaatgatga 1080 gagatcccat ctagcgtttc acgtttgcgt tctccgtcgc aactttggcg gttgttgact 1140 ttttttctta tgtcgttgtt tgactaattt tctcagagtg agagtgtaat caagaaaact 1200 aatattcgaa aagaaagaaa aaaaaggcaa gaaaactatt gtcgaaaaga cataaatgac 1260 actaaaattg gattattaaa aatggtatat atgtttggtg gaatttataa tcattaccaa 1320 aatcaaagga aggagagagg gacctcttcg tgcttatgat ttccctccta aacaactgct 1380 cccactatcc ttttttactt ccaacaaaat cattcacacg agaaaatctg tctcgtgatc 1440 actttcatgc aaaattaaac taaattttgg tattttttgt caagttcttg ctgttttaag 1500 tcgattattt ggtaatacta tatgtgtgga tatacacatc caagctaatc aataattgat 1560 ctccttctgc ttatcaataa attacaccac attagctaat caagctaata aattacacca 1620 cattctctta tcaattttta tatggtataa ataaaacaac cgactatagg ctacagagtt 1680 ggtattaagg cattattgcc ttctagtcga aggaattttt ttgttatgat aacactcgtg 1740 ggaaaaaaat ccagcctaat atgctcattt aaaggataat tgatttaaat gctttaatca 1800 ttaaaataaa aggtttttgc ttttaaaggt taccaccgct taattcatca ttaggagaat 1860 attaactttg atcgaaattc caaaatactt ttttaacaca taagaaaatt ttcagcattt 1920 ttaaataaag ggtacattta ttgggttcaa taaatatgtt tccacgtaaa gtttggaggt 1980 ttaaccacat gaatgttttt tgatttaaaa aacacataaa ttttctagta attacacatt 2040 tttaaccgtc catccagatt gtaataagtg acaaatctga aaacattttt ttttttcttg 2100 aatcttgttt aaattctctc tgctgcatac ttgcaggcat ttgaccaacg actatacata 2160 ttgaaagcaa aatatccacc agggatgata gggttagatc ccacattcaa tatcttttgt 2220 ctttgttatt tatgaaaaac aaatatttat caggaaaaaa acgtttcttc tctagtggta 2280 taagtataag ataataacaa aatttaatac ttagttaatg tatttactat cttcaaactt 2340 accatccttc aacattaata ttgatcaatt tttatttttt ttactaaact acttccacta 2400 aaaaaatgca aaagaagaga tatatattta agtcaaagta attaaagatg gatgggtgat 2460 tcttcagcaa aacggcgccg tagaggtgtc ttatcctaca ttacagctgg gttgtggcag 2520 acatcatagg gcctacgtat atttgagctt tactgtacgt aaagctttaa catatctagt 2580 tagttctcac tgtacaaaca aaacaaaatc caattcgtaa catatataca aatactacta 2640 gtactagatt acgctacgta tacatcgctt tttcgcaaat ttctaaacta atctatacaa 2700 caaacttgaa tgtttgtttt gtaatttatc ttaaaccaaa gttttgaatt gtgcattggg 2760 agctacactc tagtcccctt ttttccccaa aataatctcc ttacatcgac cggttaaagt 2820 atttaaacca acaaatttta atttgttgct gaaggtacaa acatgtcaca tatatagaga 2880 cagcatcgtt tatacaaata atgttcgatg ttattggaaa tcaaatataa atacgaatta 2940 gcgactcact tggtttaata gtttggaaga taatgaaata aaaaatgaat tcaaaggata 3000 cagagctata tatgtcgggt catttagagc cgtgaccaaa agtttcgtcg taatttctac 3060 ggtcggtcat aagaaatttt ggacttttct tcaccctttt atgaacttct gtatagtttt 3120 tgtcggatta tatatttgta ttcgtatatt ttttgtttct aataatgata cgtaaattca 3180 cgataagaaa gacttctttt tatttaattt gatttaaaac ttttgttttt ggaaatgact 3240 catacacaag gttaaagttt gatggtatcc aatttacaaa aatgtttcga gagtgcgttc 3300 gagtgtccta ccaccatcgt accaactcgt atgggtttat tattaggttt ttttcttctt 3360 tttccaatgt ctttataatt gaaccactct aaatttcttt ttttaaatta ggttaagaat 3420 cttgaatttt ctgttgattt taaaccaagg ttttcaattc ttcttagcac aaaaaaaaaa 3480 aaaaggtttt caattattaa agaatctaaa ttttttgagt tcaagagttt aatgatagct 3540 gaaaagttat gaatgattgc aagtttgcaa cagaatggtc gatgtagtac atatcaaaaa 3600 catgcatcaa aataaatatt cgtgcttagc aagagaaacg attgaaataa acagaacaat 3660 cgttaaccac ttaaaaatct tagaataatt ttgtagtgat aattttctgt aagagagagg 3720 tatcatatct tacaaaaaaa aactcatttc agataaaata atgttgtcca atcgttacca 3780 agtatgtttt tgctgtcatc agttgtattg taactcgtct cttagccata tagttctaag 3840 ttttaaatgt tttcaaagac tttacaaaaa taaaataata ataaggtgga atttgtaggg 3900 ctaaaagcga aaaataaaaa taaaataaaa gtaaagaaac gtctttctca ataagaacac 3960 agatcccaac ggattcaaac agcaaatttg tgctttgctc ttctctctta ttataatatc 4020 ctctcaaaaa ccctctccta tatcctccta aagcccccct tccttgtttc tctaccgcaa 4080 caaagaaaaa acaaaagttt gagaaaaatg gtgtgttcgt tgtgtaacca atgattgggt 4140 tttagcttac tacttcgaga gattataaga aagaaagagt gaagatacat tatagaaaga 4200 agagaagcag aaaccaaaaa aagaaacc 4228 4 1738 DNA Brassica napus CDS (1)..(1647) BANT, ANT ortholog from Brassica napus (Canola) 4 atg aag tct ttt tgt gat aat gat gat agt aat acg act aat ttg cta 48 Met Lys Ser Phe Cys Asp Asn Asp Asp Ser Asn Thr Thr Asn Leu Leu 1 5 10 15 ggg ttc tcg ttg tct tca aat atg ttg aaa atg ggt ggt gga gaa gct 96 Gly Phe Ser Leu Ser Ser Asn Met Leu Lys Met Gly Gly Gly Glu Ala 20 25 30 ctt tac tca tct tcg tcg tct tca gtt gca act tct tct gtt cca cca 144 Leu Tyr Ser Ser Ser Ser Ser Ser Val Ala Thr Ser Ser Val Pro Pro 35 40 45 cag ctt gtt gtt ggc gac aac agt agc aac tat gga gtt tgc tac ggt 192 Gln Leu Val Val Gly Asp Asn Ser Ser Asn Tyr Gly Val Cys Tyr Gly 50 55 60 tct aac tta gca gct agg gaa atg tat tct caa atg tct gtg atg ccc 240 Ser Asn Leu Ala Ala Arg Glu Met Tyr Ser Gln Met Ser Val Met Pro 65 70 75 80 ctc aga tct gac ggt tct ctt tgc tta atg gaa gct ctc aac aga tct 288 Leu Arg Ser Asp Gly Ser Leu Cys Leu Met Glu Ala Leu Asn Arg Ser 85 90 95 tct cac tcg aat aat cat cac cat agt caa gtt tca tct cca aag atg 336 Ser His Ser Asn Asn His His His Ser Gln Val Ser Ser Pro Lys Met 100 105 110 gaa gat ttc ttt ggg acc cat cat cac aac aca agt cac aaa gaa gcc 384 Glu Asp Phe Phe Gly Thr His His His Asn Thr Ser His Lys Glu Ala 115 120 125 atg gat ctt agc tta gat agt tta ttc tac aat acc act cat gcg cca 432 Met Asp Leu Ser Leu Asp Ser Leu Phe Tyr Asn Thr Thr His Ala Pro 130 135 140 aac aac aac acc aac ttt caa gag ttc ttt agc ttc cct caa act aga 480 Asn Asn Asn Thr Asn Phe Gln Glu Phe Phe Ser Phe Pro Gln Thr Arg 145 150 155 160 aac cac cat gag gaa gaa aca aga aac tac gag aat gac cct ggt ttg 528 Asn His His Glu Glu Glu Thr Arg Asn Tyr Glu Asn Asp Pro Gly Leu 165 170 175 aca cat gga gga ggg tct ttt aat gta ggg gta tat ggg gaa ttt caa 576 Thr His Gly Gly Gly Ser Phe Asn Val Gly Val Tyr Gly Glu Phe Gln 180 185 190 cag tca ctg agc ttg tcc atg agc cct ggg tca caa tct agc tgc atc 624 Gln Ser Leu Ser Leu Ser Met Ser Pro Gly Ser Gln Ser Ser Cys Ile 195 200 205 act gcc tct cat cac cac caa aac caa act caa aac cac cag cag atc 672 Thr Ala Ser His His His Gln Asn Gln Thr Gln Asn His Gln Gln Ile 210 215 220 tct gaa gct ttg gtc gag aca agt gct gga ttt gag aca aca aca atg 720 Ser Glu Ala Leu Val Glu Thr Ser Ala Gly Phe Glu Thr Thr Thr Met 225 230 235 240 gcg gct gct gct gca aag aag aag aga gga caa gaa gtt gtc gtt gga 768 Ala Ala Ala Ala Ala Lys Lys Lys Arg Gly Gln Glu Val Val Val Gly 245 250 255 cag aaa cag att gtt cat aga aaa tct att gat act ttt gga caa cga 816 Gln Lys Gln Ile Val His Arg Lys Ser Ile Asp Thr Phe Gly Gln Arg 260 265 270 act tcg caa tac cga ggc gtt aca aga cat aga tgg act ggt agg tat 864 Thr Ser Gln Tyr Arg Gly Val Thr Arg His Arg Trp Thr Gly Arg Tyr 275 280 285 gaa gct cat cta tgg gac aat agt ttc aag aag gaa ggt cat agc aga 912 Glu Ala His Leu Trp Asp Asn Ser Phe Lys Lys Glu Gly His Ser Arg 290 295 300 aaa gga aga caa gtt tat ctg ggg ggt tat gat atg gag gag aaa gct 960 Lys Gly Arg Gln Val Tyr Leu Gly Gly Tyr Asp Met Glu Glu Lys Ala 305 310 315 320 gct cga gca tat gat ctt gct gca ctc aag tac tgg ggt ccc tct act 1008 Ala Arg Ala Tyr Asp Leu Ala Ala Leu Lys Tyr Trp Gly Pro Ser Thr 325 330 335 cac act aat ttc tct gtg gag aat tat cag aaa gag att gat gac atg 1056 His Thr Asn Phe Ser Val Glu Asn Tyr Gln Lys Glu Ile Asp Asp Met 340 345 350 aag aac atg act cga caa gaa tat gtt gct cac ttg aga aga aaa acc 1104 Lys Asn Met Thr Arg Gln Glu Tyr Val Ala His Leu Arg Arg Lys Thr 355 360 365 agt ggt ttc tct agg ggt gct tcc atc tat aga gga gtc acc aga cat 1152 Ser Gly Phe Ser Arg Gly Ala Ser Ile Tyr Arg Gly Val Thr Arg His 370 375 380 cac cag cat gga agg tgg caa gct cgg atc ggt aga gtc gct gga aac 1200 His Gln His Gly Arg Trp Gln Ala Arg Ile Gly Arg Val Ala Gly Asn 385 390 395 400 aaa gat ctc tac ctt gga act ttc gga act caa gaa gaa gcg gcg gaa 1248 Lys Asp Leu Tyr Leu Gly Thr Phe Gly Thr Gln Glu Glu Ala Ala Glu 405 410 415 gcc tat gat gta gca gct atc aag ttc cgt ggc aca aac gcg gtg act 1296 Ala Tyr Asp Val Ala Ala Ile Lys Phe Arg Gly Thr Asn Ala Val Thr 420 425 430 aac ttt gac ata aca agg tac gat gtt gat cgc ata atg gct agt aac 1344 Asn Phe Asp Ile Thr Arg Tyr Asp Val Asp Arg Ile Met Ala Ser Asn 435 440 445 act ctc ttg tct gga gag atg gct cga agg aac agc aac agc atc gtg 1392 Thr Leu Leu Ser Gly Glu Met Ala Arg Arg Asn Ser Asn Ser Ile Val 450 455 460 gtc cgc aac att agc gac gag gaa gcc gct tta acc gct gtc gtg aac 1440 Val Arg Asn Ile Ser Asp Glu Glu Ala Ala Leu Thr Ala Val Val Asn 465 470 475 480 ggt ggt tcc aat aag gaa gtg ggt agc ccg gag agg gtt ttg agt ttt 1488 Gly Gly Ser Asn Lys Glu Val Gly Ser Pro Glu Arg Val Leu Ser Phe 485 490 495 ccg acg ata ttt gcg ttg cct caa gtt ggt ccg aag atg ttc gga gca 1536 Pro Thr Ile Phe Ala Leu Pro Gln Val Gly Pro Lys Met Phe Gly Ala 500 505 510 aat gtg gtc gga aat atg agt tct tgg act acg aac cct aat gct gat 1584 Asn Val Val Gly Asn Met Ser Ser Trp Thr Thr Asn Pro Asn Ala Asp 515 520 525 ctc aag acc gtt tct ctt act ctg ccg cag atg ccg gtt ttc gct gcg 1632 Leu Lys Thr Val Ser Leu Thr Leu Pro Gln Met Pro Val Phe Ala Ala 530 535 540 tgg gct gat tct taattcaatc taatggctaa ctctggtttt cttggtttag 1684 Trp Ala Asp Ser 545 ggtccaagtg tttaagttta tctccgggtt tatccggttt gaactacaat tcgg 1738 5 548 PRT Brassica napus 5 Met Lys Ser Phe Cys Asp Asn Asp Asp Ser Asn Thr Thr Asn Leu Leu 1 5 10 15 Gly Phe Ser Leu Ser Ser Asn Met Leu Lys Met Gly Gly Gly Glu Ala 20 25 30 Leu Tyr Ser Ser Ser Ser Ser Ser Val Ala Thr Ser Ser Val Pro Pro 35 40 45 Gln Leu Val Val Gly Asp Asn Ser Ser Asn Tyr Gly Val Cys Tyr Gly 50 55 60 Ser Asn Leu Ala Ala Arg Glu Met Tyr Ser Gln Met Ser Val Met Pro 65 70 75 80 Leu Arg Ser Asp Gly Ser Leu Cys Leu Met Glu Ala Leu Asn Arg Ser 85 90 95 Ser His Ser Asn Asn His His His Ser Gln Val Ser Ser Pro Lys Met 100 105 110 Glu Asp Phe Phe Gly Thr His His His Asn Thr Ser His Lys Glu Ala 115 120 125 Met Asp Leu Ser Leu Asp Ser Leu Phe Tyr Asn Thr Thr His Ala Pro 130 135 140 Asn Asn Asn Thr Asn Phe Gln Glu Phe Phe Ser Phe Pro Gln Thr Arg 145 150 155 160 Asn His His Glu Glu Glu Thr Arg Asn Tyr Glu Asn Asp Pro Gly Leu 165 170 175 Thr His Gly Gly Gly Ser Phe Asn Val Gly Val Tyr Gly Glu Phe Gln 180 185 190 Gln Ser Leu Ser Leu Ser Met Ser Pro Gly Ser Gln Ser Ser Cys Ile 195 200 205 Thr Ala Ser His His His Gln Asn Gln Thr Gln Asn His Gln Gln Ile 210 215 220 Ser Glu Ala Leu Val Glu Thr Ser Ala Gly Phe Glu Thr Thr Thr Met 225 230 235 240 Ala Ala Ala Ala Ala Lys Lys Lys Arg Gly Gln Glu Val Val Val Gly 245 250 255 Gln Lys Gln Ile Val His Arg Lys Ser Ile Asp Thr Phe Gly Gln Arg 260 265 270 Thr Ser Gln Tyr Arg Gly Val Thr Arg His Arg Trp Thr Gly Arg Tyr 275 280 285 Glu Ala His Leu Trp Asp Asn Ser Phe Lys Lys Glu Gly His Ser Arg 290 295 300 Lys Gly Arg Gln Val Tyr Leu Gly Gly Tyr Asp Met Glu Glu Lys Ala 305 310 315 320 Ala Arg Ala Tyr Asp Leu Ala Ala Leu Lys Tyr Trp Gly Pro Ser Thr 325 330 335 His Thr Asn Phe Ser Val Glu Asn Tyr Gln Lys Glu Ile Asp Asp Met 340 345 350 Lys Asn Met Thr Arg Gln Glu Tyr Val Ala His Leu Arg Arg Lys Thr 355 360 365 Ser Gly Phe Ser Arg Gly Ala Ser Ile Tyr Arg Gly Val Thr Arg His 370 375 380 His Gln His Gly Arg Trp Gln Ala Arg Ile Gly Arg Val Ala Gly Asn 385 390 395 400 Lys Asp Leu Tyr Leu Gly Thr Phe Gly Thr Gln Glu Glu Ala Ala Glu 405 410 415 Ala Tyr Asp Val Ala Ala Ile Lys Phe Arg Gly Thr Asn Ala Val Thr 420 425 430 Asn Phe Asp Ile Thr Arg Tyr Asp Val Asp Arg Ile Met Ala Ser Asn 435 440 445 Thr Leu Leu Ser Gly Glu Met Ala Arg Arg Asn Ser Asn Ser Ile Val 450 455 460 Val Arg Asn Ile Ser Asp Glu Glu Ala Ala Leu Thr Ala Val Val Asn 465 470 475 480 Gly Gly Ser Asn Lys Glu Val Gly Ser Pro Glu Arg Val Leu Ser Phe 485 490 495 Pro Thr Ile Phe Ala Leu Pro Gln Val Gly Pro Lys Met Phe Gly Ala 500 505 510 Asn Val Val Gly Asn Met Ser Ser Trp Thr Thr Asn Pro Asn Ala Asp 515 520 525 Leu Lys Thr Val Ser Leu Thr Leu Pro Gln Met Pro Val Phe Ala Ala 530 535 540 Trp Ala Asp Ser 545 6 33 DNA Artificial Sequence Description of Artificial Sequenceconsensus ANT polynucleotide sequence 1, primer used to screen/isolate ANT orthologs 6 atgaagtctt tttgtgataa tgatgatagt aat 33 7 39 DNA Artificial Sequence Description of Artificial Sequenceconsensus ANT polynucleotide sequence 2, primer used to screen/isolate ANT orthologs 7 acgactaatt tgttagggtt ctcattgtct tcaaatatg 39 8 38 DNA Artificial Sequence Description of Artificial Sequenceconsensus ANT polynucleotide sequence 3, primer used to screen/isolate ANT orthologs 8 agaatcagcc caagcagcga aaaccggcat ctgcggca 38 

What is claimed is:
 1. A method of modulating cell proliferation in a plant, the method comprising introducing into the plant an expression cassette comprising a plant promoter operably linked to a heterologous AINTEGUMENTA (ANT) nucleic acid encoding an ANT polypeptide at least 80% identical to SEQ ID NO:2 or SEQ ID NO:5; and selecting a plant with altered cell number.
 2. The method of claim 1, wherein the modulated cell proliferation results in altered plant size, mass or fertility; and the method comprises the step of selecting plants with altered size, mass or fertility.
 3. The method of claim 1, wherein ANT nucleic acid expression is increased and the method comprises the step of selecting plants with increased cell number.
 4. The method of claim 2, wherein size or mass of a plant organ is increased.
 5. The method of claim 2, wherein fertility is decreased.
 6. The method of claim 3, wherein the ANT nucleic acid is as shown in SEQ ID NO:1.
 7. The method of claim 3, wherein the ANT nucleic acid encodes a polypeptide as shown in SEQ ID NO:2.
 8. The method of claim 3, wherein the ANT nucleic acid is as shown in SEQ ID NO:4.
 9. The method of claim 3, wherein the ANT nucleic acid encodes a polypeptide as shown in SEQ ID NO:5.
 10. The method of claim 3, wherein the ANT nucleic acid expression is increased in a shoot vegetative organ.
 11. The method of claim 3, wherein the ANT nucleic acid expression is increased in a root.
 12. The method of claim 3, wherein the ANT nucleic acid expression is increased in a floral organ.
 13. The method of claim 3, wherein the ANT nucleic acid expression is increased in a seed.
 14. The method of claim 3, wherein the ANT nucleic acid expression is increased in a fruit.
 15. The method of claim 1, wherein ANT nucleic acid expression is decreased and the method comprises the step of selecting plants of decreased cell number.
 16. The method of claim 15, wherein the ANT nucleic acid is as shown in SEQ ID NO:1.
 17. The method of claim 15, wherein the ANT nucleic acid encodes a polypeptide as shown in SEQ ID NO:2.
 18. The method of claim 15, wherein the ANT nucleic acid is as shown in SEQ ID NO:4.
 19. The method of claim 15, wherein the ANT nucleic acid encodes a polypeptide as shown in SEQ ID NO:5.
 20. The method of claim 15, wherein the ANT nucleic acid expression is decreased in a shoot vegetative organ.
 21. The method of claim 15, wherein the ANT nucleic acid expression is decreased in a root.
 22. The method of claim 15, wherein the ANT nucleic acid expression is decreased in a floral organ.
 23. The method of claim 15, wherein the ANT nucleic acid expression is decreased in a seed.
 24. The method of claim 15, wherein the ANT nucleic acid expression is decreased in a fruit.
 25. The method of claim 1, wherein the plant promoter is a constitutive promoter.
 26. The method of claim 1, wherein the plant promoter is an inducible promoter.
 27. The method of claim 1, wherein the plant promoter is a tissue specific promoter.
 28. The method of claim 27, wherein the promoter directs expression of the ANT nucleic acid in a shoot vegetative organ and the method includes the step of selecting plants with altered shoot vegetative organ size or mass.
 29. The method of claim 27, wherein the promoter directs expression of the ANT nucleic acid in a root and the method includes the step of selecting plants with altered root size or mass.
 30. The method of claim 27, wherein the promoter directs expression of the ANT nucleic acid in floral organs and the method includes the step of selecting plants that are sterile, or with altered floral organ size or mass.
 31. The method of claim 27, wherein the promoter directs expression of the ANT nucleic acid in ovules and the method includes the step of selecting plants that are female sterile, or with altered ovule organ size or mass.
 32. The method claim 27, wherein the promoter directs expression of the ANT nucleic acid in anthers and the method includes the step of selecting plants that are male sterile, with altered anther organ size or mass, or with anthers that do not dehisce.
 33. The method of claim 27, wherein the promoter directs expression of the ANT nucleic acid in seeds and the method includes the step of selecting plants with altered seed size or mass.
 34. The method of claim 27, wherein the promoter directs expression of the ANT nucleic acid in fruits and the method includes the step of selecting plants with altered fruit size or mass.
 35. The method of claim 1, wherein the plant promoter is from an Arabidopsis ANT gene.
 36. The method of claim 35, wherein the plant promoter is as shown in SEQ ID NO:
 3. 37. A method of modulating cell proliferation in a plant, the method comprising introducing into the plant an expression cassette comprising a plant promoter operably linked to an AINTEGUMENTA (ANT) nucleic acid encoding an ANT polypeptide at least 80% identical to SEQ ID NO:2 or SEQ ID NO:5, wherein ANT nucleic acid expression is increased above the level of expression of an ANT nucleic acid in a wildtype, non-transgenic plant.
 38. The method of claim 37, wherein the ANT nucleic acid is as shown in SEQ ID NO:1.
 39. The method of claim 37, wherein the ANT nucleic acid encodes a polypeptide as shown in SEQ ID NO:2.
 40. The method of claim 37, wherein the ANT nucleic acid is as shown in SEQ ID NO:4.
 41. The method of claim 37, wherein the ANT nucleic acid encodes a polypeptide as shown in SEQ ID NO:5.
 42. The method of claim 15, wherein the plant promoter is in a sense orientation relative to the ANT nucleic acid.
 43. The method of claim 15, wherein the plant promoter is in an antisense orientation relative to the ANT nucleic acid.
 44. The method of claim 1, wherein the ANT polypeptide is at least 80% identical to SEQ ID NO:2.
 45. The method of claim 1, wherein the ANT polypeptide is at least 80% identical to SEQ ID NO:5. 